Loop antenna



FIG. 1 is a perspective view of the top, front and right side of a loop antenna showing my new design;

FIG. 2 is a front elevational view, the rear elevational view being identical thereof;

FIG. 3 is a right side elevational view, the left side elevational view being identical thereof;

FIG. 4 is a top plan view thereof; and,

FIG. 5 is a bottom plan view thereof.

The broken line showing of environmental structure is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a loop antenna, as shown and described. 